Abstract: A method and a device for detecting Inband Optical Signal to Noise Ratio (OSNR) are provided in the present invention, wherein the method includes the following steps: obtaining a signal power PCW1 of a first optical signal at a transmitting end, a signal power PCW2 of a second optical signal at the transmitting end, and a total signal power PS; obtaining a ratio k1 of the PCW2 to the PS and a ratio k2 of the PCW1 to the PCW2 according to the PCW1, PCW2 and PS; obtaining a signal power P?CW1 of the first optical signal at a detection point and a signal power P?CW2 of the second optical signal at the detection point; obtaining a ratio K3 of the P?CW1 to the P?CW2 according to the P?CW1 and the P?CW2; and obtaining the Optical Signal to Noise Ratio according to the k1, k2, and k3.

Abstract: The present invention provides optical power adjustment method for EPON system, and OLT. The method comprises: OLT starting optical power adjustment procedure after ONU or ONT successfully registers, receiving upstream data from the ONU or the ONT (201); during optical power adjustment procedure, OLT detecting whether there is error code in upstream data; if not, notifying the ONU or the ONT to decrease transmission optical power progressively, during progressive decrease procedure, OLT continuing to detect whether there is error code in upstream data (203); if there is error code during progressive decrease procedure, notifying the ONU or the ONT to increase transmission optical power progressively, and during progressive increase procedure, OLT continuing to detect whether there is error code in upstream data (205); if there is no error code during progressive increase procedure, OLT stopping the adjustment (207).

Abstract: An example apparatus includes a mode selective detector, a measurement module, a difference calculator and a threshold and alarm module. The mode selective detector detects a plurality of modes of a spatially multiplexed signal. The measurement module measures a parameter for the plurality of modes of the spatially multiplexed signal, wherein the parameter is a power or a signal to noise ratio (SNR). The difference calculator compares the measured parameter among a subset modes and/or among a known set of unperturbed parameters and determines a differential, the subset including at least one mode. The threshold and alarm module sets an alarm indicator when the differential is out of bounds.

Abstract: An apparatus and method of pre-emphasising a launch power profile of a section in an optical network is provided. The method comprises measuring the output power at the output of the section, determining the predicted output power associated with a flat launch power profile using design characteristics of the section and determining the total power deviation between the measured output power and the predicted output power. Also, the method comprises determining the signal to noise ratio deviation and the nonlinear phase shift deviation as a function of the total power deviation, and pre-emphasising the launch power profile based on a function of the calculated signal to noise ratio deviations of each span and the calculated nonlinear phase shift deviations of each span, such that the sum of the nonlinear phase shift deviations and the sum of the signal to noise ratio deviations of each channel are reduced by an equal amount.

Abstract: An optical communication system has a receiver that includes a plurality of photon counting sensors that each receive photons and generate pulses based on the received photons, and an electronic circuit that aggregates the number of pulses from the plurality of photon counting sensors into a merged pulse count. A demodulator samples the merged pulse count at predetermined time intervals to determine a number of photons received by the plurality of photon counting sensors during different sampling time intervals.

Abstract: Methods and systems for mitigating degradation of an optical signal-to-noise ratio (OSNR) induced by polarization dependent loss (PDL) in an optical network include determining an increase in power (?P) corresponding to a PDL-induced decrease in OSNR for a given channel being transmitted over an optical signal transmission path. The increase in power (?P) may be adjusted for at least some of the network nodes in the optical signal transmission path. At certain network nodes, the increase in power (?P) may be realized with a combination of attenuation and gain.

Abstract: Systems and method for monitoring an optical power of a dual-polarization signal are disclosed. The systems and methods may include measuring a first parameter set associated with a supervisory signal, the supervisory signal being communicated in-band with the dual-polarization signal; calculating a second parameter set from the first parameter set; calculating an intensity value from the second parameter set, the intensity value associated with one of the polarization states of the dual-polarization signal; and estimating a signal power associated with the supervisory signal from the intensity value.

Abstract: An optical power monitor that detects optical power of respective wavelengths of a signal light in a wavelength multiplexing system, includes: a light emitter configured to superimpose a frequency modulation component on a signal light; a wavelength tunable filter configured to sweep a pass band of the signal light across a wavelength band for a signal light; and a detector configured to detect intensity changes in optical power passing through the wavelength tunable filter with a frequency modulation of the optical power, and to detect an optical power measurement value at a middle point of two points of the intensity changes of the optical power as the optical power of a wavelength to be measured.

Abstract: A system includes two optical modules that perform auto-setting of the optical links between the optical modules. One optical module sends an optical signal with a test pattern to the other optical module. If the receiving module determines that the test pattern is successfully received, it sends a pass indication to the transmitting module, and the transmitting module can configure its driver path in accordance with a transmit current setting used to transmit the test pattern. If the test pattern is not successfully received, the receiving module sends a fail indication, and the transmitting module can increase the transmit current setting and resend the test pattern. When the system includes multiple optical channels, one channel can be tested while feedback is provided on another channel. The system can iterate through all optical channels until they are all configured.

Abstract: The present invention discloses a method and an apparatus for detecting an optical signal-to-noise ratio, a node device, and a network system. The method includes: receiving a detected optical signal carrying amplified spontaneous emission ASE noise; detecting a first alternating current component and a first direct current component of the detected optical signal; acquiring first modulation information of the detected optical signal; acquiring first correction information corresponding to the first modulation information according to the first modulation information; and determining an optical signal-to-noise ratio OSNR of the detected optical signal according to the first alternating current component, the first direct current component, and the first correction information.

Abstract: Changes in a signal are detected. The signal is repeatedly sampled in a synchronous manner during a predetermined interval to generate a captured eye diagram. At least one of a positive differential eye diagram or a negative differential eye diagram is generated from the captured eye diagram and a baseline eye diagram. The at least one positive or negative differential eye diagram is analyzed to determine whether a change in signal conditions is present.

Abstract: One embodiment is a Poisson-based communication system. The system includes a receiver that comprises a photodetector that receives photons and generates pulses based on the received photons, a sampling event counter that counts the number of generated pulses by the photodetector and a demodulator. The demodulator samples the sampling event counter at predetermined time intervals to determine an occurrence of a first state when light pulse energy has been transmitted by a transmitter and received by the photodetector and an occurrence of a second state when light pulse energy has not been transmitted by the transmitter and received by the photodetector.

Abstract: Methods and systems for mitigating degradation of an optical signal-to-noise ratio (OSNR) induced by polarization dependent loss (PDL) in an optical network include determining an increase in power (?P) corresponding to a PDL-induced decrease in OSNR for a given channel being transmitted over an optical signal transmission path. The increase in power (?P) may be adjusted for at least some of the network nodes in the optical signal transmission path. At certain network nodes, the increase in power (?P) may be realized with a combination of attenuation and gain.

Abstract: Described herein is an optical channel monitor (1) including one or more input optical ports (3) for receiving an input optical signal (5) including a plurality of optical channels. A first monitoring module (7) is configured to selectively scan a predetermined spectral region of the optical signal including at least one optical channel for low resolution monitoring. A second monitoring module (11) is configured to simultaneously scan a subregion within the predetermined spectral region for high resolution monitoring.

Abstract: Systems and method for monitoring an optical power of a dual-polarization signal are disclosed. The systems and methods may include measuring a first parameter set associated with a supervisory signal, the supervisory signal being communicated in-band with the dual-polarization signal; calculating a second parameter set from the first parameter set; calculating an intensity value from the second parameter set, the intensity value associated with one of the polarization states of the dual-polarization signal; and estimating a signal power associated with the supervisory signal from the intensity value.

Abstract: The present disclosure includes a method of determining optical signal-to-noise ratio (OSNR) of a signal, comprising separating one polarization component from a plurality of polarization components in an optical signal, selecting one wavelength from a plurality of wavelengths in the optical signal, delaying a first portion of the one polarization component of the one wavelength of the optical signal, shifting a phase of the first portion by a first amount and the first amount plus pi radians, causing the first portion to interfere with a second portion, measuring a power of the interference of the first and second portions, receiving the power of the interference, and comparing the power of the interference when the phase is shifted by the first amount with the interference when the phase is shifted by the first amount plus pi radians to determine OSNR. The present disclosure also includes associated devices.

Abstract: Methods and systems for asymmetrically compensating degradation of an optical signal-to-noise ratio (OSNR) induced by polarization dependent loss (PDL) in dual-polarization optical system include using an OSNR compensator. The OSNR compensator may separate the dual-polarization components and determine which component has degraded OSNR. The degraded component may be OSNR compensated using a phase-sensitive amplifier and/or a regenerator with a phase-sensitive amplifier.

Abstract: A method for determining an optical signal-to-noise ratio penalty as a measure for a quality of an optical signal transmitted via an optical link between a source optical node and a destination optical node in an optical network, the method includes collecting information of the optical link; determining a configuration parameter Pconf of the optical link based on the information of the optical link; adjusting the configuration parameter Pconf to an adjusted configuration parameter P?conf according to linear impairments in the optical link; and determining the optical signal-to-noise ratio penalty based on a non-linear function of the adjusted configuration parameter P?conf, the non-linear function accounting for non-linear impairments in the optical link.

Abstract: An optical amplifier that uses software-defined optical networking (SDON) technology, with a centralized controller and flexible physical hardware (the adaptive amplifier here) to optimize the power distribution among different WDM channels in the amplifier. It considers the detailed information for each channel through the information from centralized controller. It is suitable for both single line rate and mixed line rate system, and is suitable for a wavelength division multiplexing WDM system with the same signal type or different signal types.

Abstract: A path computation client (PCC) can request a path computation element (PCE) to compute a path across a wavelength switched optical network. PCC sends a request which identifies end nodes. The end nodes can support a plurality of possible values of a transmission parameter, such as modulation format or Forward Error Correction (FEC) type. The PCE computes a path between the end nodes and sends a reply to the PCC. The reply identifies the path between the end nodes and identifies a selected value of the transmission parameter for the computed path. The reply can comprise a spectrum assignment for the path. The reply can be a PCE Communication Protocol (PCEP) Reply message.

Abstract: There is provided a method and an apparatus for determining quality parameters on a polarization-multiplexed optical signal based on an analysis of the power spectral density of the Signal-Under-Test (SUT). The method is predicated upon knowledge of the spectral shape of the signal in the absence of significant noise or spectral deformation. This knowledge is provided by a reference optical spectrum trace. Based on this knowledge and under the assumption that ASE noise level is approximately constant in wavelength over a given spectral range, the spectral deformation of the signal contribution of the SUT may be estimated using a comparison of the spectral variations of the optical spectrum trace of the SUT with that of the reference optical spectrum trace.

Abstract: A system and method is disclosed that allows for the monitoring, analyzing and reporting on performance, availability and quality of optical network paths. The correlation of PM parameter metrics to client connections, coupled with threshold-based alarm generation provides a proactive and predictive management, reporting and analyzing of the health and effectiveness of individual path connections to alert Operational Support (OS) staff and/or customers to signal degradation and impending Network Element (NE) failures. The system and method performs in real-time processing intervals required for alarm surveillance in a telecommunications network.

Abstract: Embodiments of the present invention provide a method and an apparatus for equalizing link performance, and relate to the field of optical wavelength division multiplexing. In the present invention, target input power spectra and target output power spectra in all OMS sections in a network and single wave attenuation at a power adjusting point may be concurrently calculated based on link information of the OMS sections, fast adjustment may also be implemented for a complex network topology, and the adjustment may be implemented in a one-off manner to avoid a problem that iteration adjustment is caused by mutual impact of power adjusting points during serial adjustment in a ring network. In addition, it is not required to connect an optical path in the calculation phase, thereby eliminating reliance on a connected optical path in a process for equalizing link performance.

Abstract: An optical signal quality monitoring apparatus includes an optical detector for directly receiving an optical signal modulated in an optical path and converting the optical signal to an electric signal, an asynchronous sampling unit for asynchronously sampling the electric signal of the optical detector at a reduced speed, and a digital signal processor for monitoring an optical signal quality by finding a synchronized amplitude histogram of data sampled in the asynchronous sampling unit. An optical signal quality monitoring method includes (a) a step of allowing an optical detector to directly receive a modulated optical signal and to convert the optical signal to an electric signal; (b) a step of allowing an asynchronous sampling unit to asynchronously sample the electric signal; and (c) a step of allowing a digital signal processor to monitor an optical signal quality by generating a synchronized amplitude histogram of sampled data.

Abstract: A transmission apparatus includes: an amplifier controller configured to determine a target value for an average optical input power of a transmitting amplifier in a transmitting-side apparatus, based on an index based on a quality of transmission from an output of the transmitting amplifier to an output of a receiving amplifier in a receiving-side apparatus; and a pre-emphasis controller configured to determine amounts of adjustment of transmission optical powers for respective wavelengths, based on the target value and per-wavelength reception optical powers at the output of the receiving amplifier.

Abstract: A measurement device includes a first obtaining unit configured to obtain a first power ratio that indicates a ratio of optical signal power of a first wavelength in a first spectrum at a reception device to optical signal power of a second wavelength different from the first wavelength in the first spectrum; a second obtaining unit configured to obtain a second power ratio that indicates a ratio of optical signal power of the first wavelength in a second spectrum at a transmission device to optical signal power of the second wavelength in the second spectrum; a calculation unit configured to calculate an OSNR of the optical signal at the reception device using the first power ratio obtained by the first obtaining unit and the second power ratio obtained by the second obtaining unit; and an output unit configured to output the OSNR calculated by the calculation unit.

Abstract: Methods and apparatuses are provided to employ an enhanced Loss of Signal (ELOS) function in network equipment (NE) such as an Ethernet switch that is coupled to an optical path by a transceiver (e.g., an SFP). Diagnostics such as optical path receive (Rx) level from the transceiver are used by the ELOS function to regenerate LOS status from the transceiver when either LOS or designated low Rx level conditions exist. By generating an enhanced LOS (ELOS) on a designated low Rx level, the ELOS function ensures a failing data path is removed before an undesirable amount of errors occur to enhance Ethernet path selection and improve Carrier Ethernet quality of service.

Abstract: A technique for monitoring at least a network portion of an optical communication network, by monitoring changes of a decision threshold used for discriminating a digital optical signal being propagated via the network portion.

Abstract: A method includes generating a test signal and modulating the test signal. The method may also include transmitting the test signal on an optical path, where the optical path may include a number of add-drop multiplexer devices and amplifiers. The method may also include receiving the test signal at a destination device and converting the received test signal into an electrical signal. The method may further include identifying a portion of the electrical signal that is associated with the modulated test signal.

Abstract: A hybrid communications system implements different communication technologies to communicate data and information for particular communications directions in different portions of the system. Power line communications (PLC) signaling is used to deliver data and information from a gateway device to a light access point. Visible light communications (VLC) signaling is used to communicate data and information from the light access point to a user equipment (UE) device. Wireless radio signaling, wireless infrared (IR) signaling, or a combination of wireless IR signaling and PLC signaling is used to communicate data/information from the UE device to the gateway device. To efficiently control the VLC communications channel between the light access point and UE device, the UE device measures the VLC channel, e.g., calculating SNRs on a per VLC tone basis, and communicating VLC channel quality feedback information to the gateway device, which is forwarded to the light access point.

Abstract: A WDM optical signal is transmitted through a tunable optical filter and is polarization-nulled to find optical signal to noise ratio of individual WDM channels. The polarization nulling can be performed using a heuristic multipoint extrema search method, such as Nelder-Mead method. A plurality of checkpoints can be included in the search to verify the progress and to improve the overall robustness of a real-time polarization nulling.

Abstract: An optical packet switching system includes an optical packet generator for generating an optical packet signal, an optical packet switching unit, provided with an optical switch, for switching the route of an inputted optical packet signal by controlling on/off of the optical switch, and an optical signal-to-noise ratio measuring unit for measuring the optical signal-to-noise ratio of the optical packet signal outputted from the optical packet switching unit. When switching the route of the optical packet signal, the optical packet switching unit outputs an optical packet signal with optical noise by keeping the optical switch on longer than the time width of the packet signal. The optical signal-to-noise ratio measuring unit measures the optical signal power and the optical noise power, respectively, in the optical packet signal with optical noise and measures the optical signal-to-noise ratio by calculating the ratio between the optical signal power and the optical noise power.

Abstract: The optical receiver includes: a photoelectric conversion circuit for receiving an optical signal and converting the received optical signal into an electrical signal; a comparator for outputting a first determination signal (S1) when a voltage corresponding to the optical signal does not reach a first threshold value (TH1) and for canceling an output of the S1 when the voltage corresponding to the optical signal exceeds a second threshold value larger than TH1 during the S1 is output; a timing extraction circuit for generating a clock signal based on a frequency and a phase of the electrical signal obtained by the converting and for outputting a second determination signal (S2) when the generated clock signal does not satisfy a predetermined condition; a unit for causing the comparator to output the S1 when the S2 is output; and detects loss of optical signal while one of the S1 and S2 is output.

Abstract: There is provided a method for determining the in-band noise in agile multichannel Dense Wavelength Division Multiplexing (DWDM) optical systems, where the interchannel noise is not representative of the in-band noise in the optical channel. The method relies on the analysis of two observations of the same input optical signal. In the two observations, the linear relationship between the optical signal contribution and the optical noise contribution (e.g. the observed OSNR) is different, which allows the discrimination of the signal and noise contributions in the input optical signal. In a first approach, the two observations are provided by polarization analysis of the input optical signal. In a second, the input optical signal is obtained using two different integration widths.

Abstract: An apparatus and method of pre-emphasising a launch power profile of a section in an optical network is provided. The method comprises measuring the output power at the output of the section, determining the predicted output power associated with a flat launch power profile using design characteristics of the section and determining the total power deviation between the measured output power and the predicted output power. Also, the method comprises determining the signal to noise ratio deviation and the nonlinear phase shift deviation as a function of the total power deviation, and pre-emphasising the launch power profile based on a function of the calculated signal to noise ratio deviations of each span and the calculated nonlinear phase shift deviations of each span, such that the sum of the nonlinear phase shift deviations and the sum of the signal to noise ratio deviations of each channel are reduced by an equal amount.

Abstract: A node apparatus is installed at a node located on a route from a start node to an end node, and includes: a parameter calculating unit configured to, upon receiving routing information specifying the route and a first parameter representing an amount of signal degradation, update the first parameter by using a second parameter representing an amount of signal degradation along a transmission route to an adjacent node, and generate a third parameter representing an amount of signal degradation along a transmission route between the start node and the node, specified by the routing information; and a determination unit configured to determine reachability of the route specified by the routing information in accordance with the third parameter and a fourth parameter representing an amount of signal degradation along a transmission route from the node to the end node specified by the routing information.

Abstract: Signals propagating in wavelength division multiplexing (WDM) optical networks suffer from loss, which decreases optical signal-to-noise ratios (OSNRs) and degrades a quality of received transmissions. Present methods of boosting OSNRs involve regeneration using transponders, which scale in complexity with the number of WDM channels. Optical amplifiers may boost signal strength, but amplified spontaneous emission (ASE) noise often reduces OSNR despite increases in signal strength, although changing the amplifier operating settings may reduce emitted ASE noise power. A method or corresponding apparatus in an example embodiment of the present invention provides a planning tool for deploying optical amplifiers in an optical network in a manner that reduces the need for optical regeneration, reducing cost and complexity of the deployed network.

Abstract: Systems and methods for monitoring the accuracy of a global positioning system (GPS) receiver in a marine vessel utilize a GPS receiver receiving a plurality of satellite signals, calculating a global position of the GPS receiver based on the plurality of signals, and determining a signal to noise ratio (SNR) of each signal in the plurality of signals; and a control circuit having a computer readable medium having executable code, and being connected to the GPS receiver by a communication link. The control circuit calculates an average SNR of the plurality of signals and compares the average SNR to a threshold SNR. In one example the threshold SNR varies depending upon a number of satellites sending the plurality of signals and a speed at which the marine vessel is traveling.

Abstract: An optical receiver includes a converter configured to convert, into an electrical signal, an optical signal including error correction information, the optical signal being received from a transmitting side; a corrector configured to correct an error on the electrical signal, based on the error correction information; a threshold controller configured to control a threshold value discriminating a power of the electrical signal, based on a result of the error correction; a table configured to form therein data of a relationship between the threshold value and a power of an optical noise occurring when the optical signal is amplified within an optical transmission path; and a deriving unit configured to obtain the power of the optical noise corresponding to the threshold value from the table.

Abstract: There is provided a method of determining at least one linear-crosstalk-related parameter of an optical signal-under-test having, within an optical channel bandwidth, at least a data-carrying signal contribution and a wavelength-dependent linear-crosstalk contribution arising from a data-carrying signal contribution of an adjacent optical signal associated with an adjacent channel to the optical signal-under-test, the method comprising: acquiring at least one optical spectrum trace encompassing a quasi-continuum of closely-spaced wavelengths over a spectral range extending to at least part of both the signal under test and the adjacent optical signal; and estimating said linear-crosstalk contribution using at least spectral properties of said at least one optical spectrum trace; wherein one of said at least one linear-crosstalk-related parameter is the linear-crosstalk contribution and is determined from said estimating.

Abstract: For an optical network link, a receiving node monitors optical performance and upon determination of lowered optical performance for an extended period of time, the node can signal a transmitting node to lower bit transfer rate from a nominal bit transfer rate. The receiving node has a transponder which has a digital electronic variable bandwidth filter to process the digitized signals at the lowered bit transfer rate to increase the SNR of the signals. Optical performance of the link is optimized although at the lowered bit transfer rate.

Abstract: One measurement system comprises a polarimeter with a polarimeter detector bandwidth that partially overlaps with a signal bandwidth or completely overlaps with a signal bandwidth. The polarimeter measures a state of polarization (SOP) or a degree of polarization (DOP) of the signal in the presence of noise. The system further comprises a sampler that receives polarimeter signals from the polarimeter and samples those received signals at a specified sampling rate. The sampler outputs sampled data to a processor that calculates a mean DOP for the samples. Subsequently, the OSNR is determined from the calculated mean DOP.

Abstract: Embodiments of the present invention disclose a path selecting method and apparatus. The method includes: computing an end-to-end path for a newly added service according to network topology and a wavelength constraint, and assigning a wavelength to the path; computing performance of each existing service and performance of the newly added service in a network according to physical impairment information collected in the network, where the physical impairment information includes a gain reference spectrum of each optical amplifier in the network; and performing impairment check on performance of each service, and performing path selection for the newly added service according to a result of the impairment check. The apparatus includes a path computation module, a performance computation module and an impairment check module. According to the embodiments, efficiency of network update or rerouting is improved.

Abstract: A method of monitoring optical parameters of a modulated optical signal comprises receiving a first optical power, Xi, of said optical signal for a first bandwidth, Bi, across the said optical signal and receiving a second optical power, Xj, of said optical signal for a second bandwidth, Bj, across the said optical signal. The method comprises obtaining a power spectral density description of said optical signal. The method comprises determining an optical signal to noise ratio of said optical signal. The optical signal to noise ratio depends on said first optical power, Xi, said second optical power, Xj, and said power spectral density description. The method also comprises generating a data signal indicative of said optical signal to noise ratio.

Abstract: The invention provides a system and method for measuring optical signal-to-noise-ratio (OSNR) in an optical communication system. A channel filter is adapted to select one specific optical communication channel from a wavelength-division-multiplexing (WDM) optical communication system, wherein the channel comprises an optical signal carrying digital bit information and noise from associated optical power amplifiers in the system. At least one optical delay interferometer is adapted to measure at least two interferograms of the noisy signal. The invention provides a mechanism for calculating the in-band OSNR from extinctions of the interferograms measured at different optical delays by referring to each other, wherein said optical delays are selected to be substantially less than a bit period of the optical channel.

Abstract: For determining OSNRreal of a real optical signal carried in an optical network link, the following has been proposed: tapping a portion of the real optical signal, altering the tapped signal portion by adding to it in-band artificial noise signal, thus obtaining a combined signal, scattering the combined signal by stimulated Brillouin or Raman scattering (SBS or SRS) in an optical element, extracting a signal back reflected by SBS/SRS from the optical element, determining OSNRcomb of the back reflected signal and deriving the OSNRreal from the OSNRcomb knowing absolute and/or relative power of the added artificial noise.

Abstract: Consistent with the present disclosure, based on system requirements or in response to an increase in optical signal-to-noise level of an optical channel, such as a WDM channel, additional FEC bits are inserted into and replace selected data payload bits in each frame carried by the channel. The replaced data payload bits may then be transmitted in subsequent frames on the same channel. As a result, the transmitted frames have a reduced data payload rate, but a higher coding gain. Alternatively, the replaced data payload bits may be included in frames transmitted on another optical channel. In that case, the frames carried by the two channels typically have the same bit length or number of bits and may thus be compliant with the frame length requirements of G.709, for example. Preferably, the number of coding bits may be changed dynamically to obtain different coding gains.

Abstract: An OSNR monitor device includes an optical receiver including a delay interferometer which inputs an optical signal in accordance with a given bandwidth and outputs two optical signals and causes the optical signals to interfere with each other and optical detectors which outputs currents in accordance with optical powers of the optical signals output from the interferometer, an optical power monitor configured to obtain the optical powers of the optical signals received by the optical detectors included in the optical receiver, and an OSNR calculator configured to calculate an optical signal-to-noise ratio in accordance with the optical powers obtained from the optical power monitor and the reception bandwidth.

Abstract: In accordance with an embodiment of the present disclosure a method for adaptively spacing channels of an optical network comprises determining a first desired power level of a first channel of an optical network. The method further comprises determining a second desired power level of a second channel of the optical network, the second desired power level being less than the first desired power level. Additionally, the method comprises determining a first spectral space between the first channel and one or more channels neighboring the first channel based at least on the first desired power level. The method also comprises determining a second spectral space between the second channel and one or more channels neighboring the second channel based at least on the second desired power level, the second spectral space less than the first spectral space.

Abstract: The present disclosure provides a method for monitoring and adjusting optical power, where the method includes: according to a characteristic of a service, calculating a degraded coefficient corresponding to each service; according to a nominal signal-to-noise ratio input and a nominal power input which are between nodes, calculating a nominal signal-to-noise ratio output between the nodes; according to the nominal signal-to-noise ratio input and the nominal signal-to-noise ratio output between the nodes, calculating a nominal degraded degree of an OSNR between the nodes; according to the degraded coefficient corresponding to each service, and the nominal degraded degree of the OSNR between the nodes, calculating a target degraded degree of each service between the nodes; according to the target degraded degree of each service between the nodes, calculating a target optical power adjusting value of each service at a sending end node; and adjust optical power of each service.